%I A054583
%S A054583 1,3,280,6028059
%N A054583 Number of nonisomorphic acyclic orientations of the Hamming graph (K_n) 
               x (K_n).
%C A054583 Also number of plans (i.e. structural solutions) of the open shop problem 
               with n jobs and n machines where the jobs may be interchanged with 
               the machines - see problems in scheduling theory.
%D A054583 H. Braesel, M. Harborth, T. Tautenhahn and P. Willenius, On the set of 
               solutions of the open shop problem, Ann. Oper. Res. 92 (1999) 241-263
%D A054583 M. Harborth, Structural analysis of shop scheduling problems, PhD thesis, 
               Otto-von-Guericke-Univ. Magdeburg, GCA-Verlag, 1999 (in German)
%Y A054583 Cf. A053870.
%Y A054583 Sequence in context: A068250 A096126 A057599 this_sequence A139984 A057631 
               A058455
%Y A054583 Adjacent sequences: A054580 A054581 A054582 this_sequence A054584 A054585 
               A054586
%K A054583 nonn,nice,hard
%O A054583 1,2
%A A054583 Martin Harborth (Martin.Harborth(AT)vt.siemens.de)